Chemical compositions and distributions of nitrogen and phosphorus in Changjiang River Estuary and its adjacent east China sea
长江口及邻近水域氮、磷的形态特征及分布研究

According to the monitoring results in recent years, chemical compositions of nitrogen and phosphorus and their distribution in Changjiang River Estuary and Adjacent East China Sea had been comprehensively investigated. Nitrate nitrogen was the main chemical species and occupied about ninety percent of inorganic nitrogen in the water area. The concentration of inorganic nitrogen was the highest in the estuary , but it became more and more dilute in the southeast sea area. Total phosphorus existed in two chemical forms incluidng dissolved and particulate phosphorus. The concentration of inorganic phosphorus in the spring was higher than that in the summer. Large variation and high average values of N/P were the main characteristics of this estuary and its adjacent sea area. A positive correlation existed between the N/P and the runoff of Changjiang River. In general, the phosphorus nutrient and illumination may be the limiting factors for phytoplankton growth.